Recent advances in aromatase inhibitor therapy for breast cancer

Third-generation aromatase inhibitors (anastrozole, letrozole, and exemestane) have emerged as an alternative first-line endocrine treatment for postmenopausal breast cancer patients with hormone-responsive disease. Their clinical efficacy, excellent tolerability, and safety profile compare favorably with that of tamoxifen, which has been the cornerstone of endocrine therapy for years. This review will discuss the findings of recently published randomized clinical trials comparing this new class of drugs with tamoxifen as first-line treatment for advanced disease. We will also present the design and rationale of ongoing trials looking into the use of third-generation aromatase inhibitors in the adjuvant setting and review data regarding their possible role in premenopausal women.